from tkinter import *
from tkinter import ttk

def calculate(*args):
    try:
        value = float(display.feet.get())
        display.meters.set((0.3048 * value * 10000.0 + 0.5)/10000.0)
    except ValueError:
        pass
class display:
    root = Tk()
    root.title("Feet to Meters")

    style = ttk.Style()
    style.theme_use('default')
    
    mainframe = ttk.Frame(root, padding="3 3 12 12")
    mainframe.grid(column=0, row=0, sticky=(N, W, E, S))
    mainframe.columnconfigure(0, weight=1)
    mainframe.rowconfigure(0, weight=1)

    feet = StringVar()
    meters = StringVar()
    feet_entry = ttk.Entry(mainframe, width=7, textvariable=feet)
    feet_entry.grid(column=2, row=1, sticky=(W, E))

    ttk.Label(mainframe, textvariable=meters).grid(column=2, row=2, sticky=(W, E))
    ttk.Button(mainframe, text="Calculate", command=calculate).grid(column=3, row=3, sticky=W)

    ttk.Label(mainframe, text="feet").grid(column=3, row=1, sticky=W)
    ttk.Label(mainframe, text="is equivalent to").grid(column=1, row=2, sticky=E)
    ttk.Label(mainframe, text="meters").grid(column=3, row=2, sticky=W)
    l =Label(root, text="Starting...", width=50, bg="white", fg="brown")
    l.grid(column=1, row=3,sticky=N)
    l.bind('<Enter>', lambda e: display.l.configure(text='Moved mouse inside'))
    l.bind('<Leave>', lambda e: display.l.configure(text='Moved mouse outside'))
    l.bind('<1>', lambda e: display.l.configure(text='Clicked left mouse button'))
    l.bind('<Double-1>', lambda e: display.l.configure(text='Double clicked'))
    l.bind('<B3-Motion>', lambda e: display.l.configure(text='right button drag to %d,%d' % (e.x, e.y)))

    for child in mainframe.winfo_children(): child.grid_configure(padx=5, pady=5)

    feet_entry.focus()
    root.bind('<Return>', calculate)


